Mark Elder turns wistful as he contemplates his brief debut engagement with the Los Angeles Philharmonic. "It's an evil of our times, these promiscuous one-night stands," he says with a sigh, gazing intently out of his hotel room. "If only the planes didn't fly so often and so fast. . . . "

The jet-setting life holds little appeal for Elder. "It's a different type of music-making," he points out. "I would love to concentrate on the finesse of sound. . . . " Once again, an incomplete thought that needs no completion.

As music director of English National Opera and principal guest conductor of the BBC Symphony, the 37-year-old musician is more at home at home. "I've been conducting in London now for 10 years, and finally I'm having a real contact with the audience," he says.

Nonetheless, Elder cannot hide a certain eagerness about the Beethoven-Rachmaninoff programs with the Philharmonic tonight, Friday and Sunday at the Music Center and Saturday in Santa Ana. "The challenge of this week," he says brightly, "is to cajole out of the orchestra the closest thing to an ideal sound.

"There's a risk, of course, in working for a limited time with such a fine orchestra. It has to do with chemistry. In a way, it's like riding a horse--trying to get the feel of the animal as quickly as possible." Elder obviously enjoys this analogy, for a smile crosses his face.

Though the Philharmonic concerts represent Elder's first engagements on the West Coast, these dates are not his first in this country. Besides guest engagements with the Chicago and St. Louis symphonies, Elder last year brought English National Opera to the United States for its first tour--one steeped in controversy.

Anticipation, it may be recalled, had centered around Jonathan Miller's staging of "Rigoletto," set in New York's Little Italy. Protests by Italian-American organizations preceded the performances, though the production proved tamer than expected. "It's not important whether it's controversial. It has to be good," Elder says. "People tend to forget the musical side. This production had absolutely no cuts."

The tour proved a sobering experience for Elder. "It was an artistic success but a financial failure," he says flatly. "The governor of Texas promised us money (the six-week tour opened in Houston in May), but the funds didn't materialize."

The company hobbled back to London with a severe debt. "It gave us a knock," the conductor admits, "though it's made no change in our London status."

Of the company's rumored visit to Los Angeles last year, Elder says, "It was an interesting plan. Ernest Fleischmann (executive director of the Philharmonic) supported it. We didn't come, of course, because Covent Garden was here," a reference to Royal Opera's Olympic Arts Festival engagement in July. More significantly, the costs of a Southern California visit proved prohibitive.

Now, with the debts incurred from the American tour, Elder could not express any optimism that Los Angeles audiences would see English National Opera in the near future: "We can't seriously play a foreign tour.

"Back home, we're trying to reach young people, to extend the bounds of the elitism that surrounds opera. The company even made a 30-second commercial for itself."

Any help from the British government? A sore spot is apparently hit: Prime Minister Margaret Thatcher, Elder intones, "does not understand that you need to water your cultural institutions with funds.